I can't decide on this. It would work better in the companies where it probably already is less of an issue; I can work from home sometimes, and I and my male colleagues have all done this, including when we are feeling off-colour. In fact, the men have probably done this more than I have. We also don't have to work an exact 9-5 day, as long as we do our contracted hours or more each week.
But our job doesn't involve serving customers at the till or teaching a class full of children, or nursing patients in a hospital ward - some jobs you have to be present for to be able to do it. Flexibility and making the time up won't necessarily work - you can't teach Wednesday's 2pm class next Monday instead, because everyone will be in a different class at that point.
A couple of weeks ago, I did trigger the Bradford factor at work, because I've had 5 sick days in a rolling 12 months. One of those days was for bad period pains, but work doesn't know that - I just reported upset stomach and headache (which was true, it's just it was because of menstruation rather than a virus or bacterial infection or whatever.) I mostly do cope with my periods, with the help of tranexamic acid, and I also have a GP who says, "no woman in this day and age should have to have her life interrupted by periods!" - but not everyone has such an enlightened GP, and plenty of GPs still expect women to put up with period pain, even severe pain, because that's just part of being a woman.
When I was in my 20s, I just didn't believe that periods could be that bad, because mine weren't, and we didn't have messageboards to enlighten me otherwise back then. The only conversations I ever really had about periods were of the "have you started yet?" type, never about how heavy or not they were, what counted as heavy or anything. (Looking back, I'm not quite sure how this happened, given I was at a single-sex secondary school, but it's possible I just concentrated more on things like learning verb tables and everyone else was talking about it.) As I've got older, it's actually been a surprise to me that how my menstrual cycle manifests itself has changed so much over the years. They're a lot heavier and more painful now I'm in my 40s, but I am also far more aware of when I'm ovulating. Plus places like mumsnet has meant I've heard from a lot more women whose experiences are different, and I realise that it really can vary from something that's not really much to think about to vomiting and fainting and needing to stay within close access of the loo all day because of having to change protection so often (that bit's me these days.) And when it's bad, it is really difficult to function properly at work, if at all.
If you do get really bad periods, then I would have thought it count as a chronic condition that would be covered by the Equality Act, and I do think that menstrual problems should have some sort of exemption like that, or pregnancy-related illness, when it comes to tracking absences. But I don't see how you could plan it in advance - some people are very regular, but not everyone is, and just going by my own experience, some months are just uncomfortable, and others have been far worse, to the point where I have taken a day off - but I never know ahead of time whether it's going to be a good month or a bad month, and I don't think that's unusual.
But I do also recognise that there's great potential for prejudice against women with this sort of thing. There are still employers who think women taking maternity leave aren't dedicated to their job (and men who take paternity, going by the reaction to a Swedish colleague.) There are employers who are currently saying they can't afford to pay men paternity leave rates what they offer for maternity leave, now there is the right to shared parental leave. There would be plenty who would say they can't afford to deal with menstrual leave or flexibility. And even if there were legal measures to enforce it - well, there are plenty of employers who avoid employing women of childbearing age, and pregnant women don't seem to be less at risk of losing their job, regardless of what the law might say. The prejudice is already there.
But bad periods do happen, and women can't always just grit their teeth and work through, and I think it would be better if this was more accepted in work places. I also think talking more openly about periods at work would be a good thing, making it more normal. I don't think I have ever talked about periods at work, though I have openly carried tampons through the office. Only some of this is because I have spent most of my working life in male-dominated workplaces - even when I've been working with women, I've never discussed periods, not even in terms of "have you got a spare pad I could have?"
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